Shopping Serval Style

We are currently preparing to provide the latest Serval mesh telephony technology for use in a disaster response training exercise with a major relief agency in late February 2012 -- about two months from now.  In that time we need to not only get our prototype Field Communications Unit (FCU) kit together, but also finish some software development that is key for making the technology useful for the relief agency.  You can watch a demo of one of the features we are working on in the video below, where I send a photo from one phone to another, without infrastructure.  This is the same technology we have used to send an SMS more than 10,000km without infrastructure.

On the hardware side, we have ordered 50 Huawei IDEOS X1 phones for AUD$71.10 each -- pretty cheap for a fully featured Android smart phone, complete with digital compass, GPS, accelerometers, a capacitive screen and enough CPU and RAM to meet our needs. These phones are network locked, but that doesn't worry us as we won't ever be putting a SIM card in them, because they will be used solely as mesh communications devices.

It turns out that buying 50 phones at a time is an interesting exercise.  People want to know that you are not planning to resell them or export them.  Some shops will even try to limit you to buying five or less at a time.  Those tactics are legal in some places, but not here in sunny South Australia, where we have an excellent Fair Trading Act that correctly classifies such terms of trade as discriminatory, or in some cases as tantamount to bait-and-switch.

In fact, until quite recently the South Australian consumer protection and gambling laws were so strong that cereal-packet competitions could not require a South Australian resident to purchase a product to participate in a trade promotion lottery, because it would be considered gambling, i.e., pay for chance to win.  So when I was growing up it was quite common to see terms and conditions looking quite normal, and then have sections specially for South Australians, that would often say something along the lines of:

"10. To enter, cut the bar code from a packet of XYZ and include it in your entry as proof-of-purchase.  Residents of South Australia are permitted to submit a hand drawn facsimile of the proof-of-purchase.

...

17. Only one entry per household per day.  Residents of South Australia may enter more than once per day."

There were certainly occasions in my childhood when we would go to the effort of getting the coloured pencils out to draw a barcode by hand to get the chance to win a prize.  I think we sometimes did it just because we could.  Sadly, with the introduction of poker machines (Australia has fully 21% of the worlds poker or slot machines --- a statistic that is disturbing given that Australia has only about 1% of the developed-world population) and the general liberalisation of gambling in South Australia the situation has changed, and I believe we have lost our little parochialism.

Anyway, I digress.

After the difficulties I encountered initially in sourcing 50 mobile phones, I eventually went to our local post office to see if they would order me 50, since they had the model I wanted in their catalog.  Not only were they willing to order them (I promised to pay up-front, since it was a large purchase), they also kindly sliced 10% off the price.  So I now have a box of 44 phones in my lounge room, with the remaining 6 on back order:

At this price, the phones don't come with SD cards, which we do need for the Serval Rhizome software to do anything useful, as store-and-forward requires somewhere to store!  So I hunted around, and after some luke-warm experiences with suppliers either being unwilling to give me a decent price for what is clearly a wholesale quantity, or failing to stock enough, I tried OfficeWorks.  They had enough in stock, but were charging $16 for 4GB cards, which I had quotes from other local stores for $7.  So I loaded my basket with 50 memory cards, and proceeded to try their price-matching policy:

However, the large price difference and quantity did trigger concern from their store manager.  He was very friendly and amiable, but did point out that to get the price matched, I had to find a local supplier with the quantity I wanted actually in stock.  But that wasn't easy to arrange, as most of the cheaper suppliers only had a few on hand.  There is of course a silliness in their rule, as I could have bought them in small batches such that each batch was small enough that the cheaper shop held sufficient stock.  But in the end I did manage to find a cheap supplier on eBay who had plenty in stock at $5.80 a piece for SANDisk 4GB class 4 microSD memory cards.  Now we just have to see if they will arrive.

So that covered the phones and memory cards.  The next challenge was to come up with a way to easily charge 50 phones.  Not only did it need to work in my home, but it also had to have the potential to work in a real disaster zone, and one which might not be in Australia.  Having enough power boards to plug 50 little USB charger bricks was not an attractive option, especially since I need to fit all of this into my 23kg luggage limit when I fly, and 50 phones alone are not that light.

What I have decided to do is to chop up a pile of USB leads and wire them up to some automotive 5v accessory power supplies that are commonly used to power portable DVD players and the like.  Apart from being the cheapest 5v high-current power supplies I could find (AUD$40 for 5A), they have the benefit of running on 12v, or in the case of some models, on 12v-24v, so that they can even work in a truck.  This means that in-vehicle mass-charging is possible when the power grid is off.  It also means that they can all be charged using a single cheap 13.8v power supply, which are also quite cheap; you could even use an old computer power-supply.  You can see my prototype here:

So now I just need to get back to writing the software that needs to go on these phones ...

Demonstrating the Serval Rhizome Store-and-Forward MeshMS SMS Service

(Please take a look at our crowd-funding campaign at igg.me/at/speakfreely.)

Update: We trialled Rhizome on a training exercise in New Zealand recently.  Follow the link to read the blog post about it.

SMS messages on a cellular network get delivered via the cell towers and message centre infrastructure.

On a mesh, it is possible for us to deliver messages to other phones that are reachable on the mesh at the same time.  This works great, and we have had this capability in the Serval BatPhone software for a while now.

However, it does have some limitations, in particular, if there is no link all the way from the sender to the receiver on the mesh at the instant the message is sent.  This is rather unfortunate, as we usually think of SMS as being the most reliable fall-back on a mobile communications network.

So we set about replicating this resilience by creating a store-and-forward SMS-like service on top of the Serval Rhizome mesh file distribution framework.  We call this MeshMS, for Mesh Message Service.

This service uses direct mesh links if they are available by making use of the existing SMS capability in the Serval BatPhone software.  However, if there is no direct link, then it uses a store-and-forward scheme, that asks any passing phones to copy the message and distribute it to other phones on the mesh, until it (hopefully) eventually reaches its intended destination.  The cartoon below shows how this works.

The man wishes to send the message "Prepare the Zeppelin" to his hench-person, but there is no direct mesh link at that time due to the challenging topology.  The message gets picked up (stored) by the compatible phone in the pram, without any action on the part of the woman.  The woman then keeps walking along, and eventually the phone in the pram is able to automatically deliver (forward) the message to the ultimate destination, whereupon the minion knows to ready his master's zeppelin, to do the weekly grocery shopping, one trusts. Of course, there could be many intermediate steps, instead of just the one shown here.

The great thing about this approach is that it doesn't require a complete path to the destination at the time of sending, but can propagate progressively across the mesh as it is able, and can make use of nodes that move between otherwise isolated mesh networks, creating an asynchronous link between them where it would not otherwise be possible.

While the delay in such a service is huge, the bandwidth is also great, as potentially gigabytes of data can be transferred between nodes.  One side use of this protocol that we intend to exploit is to provide an efficient means of distributing updates to the Serval software suite, so that field updates can occur without dependence on infrastructure, and with much greater aggregate bandwidth than any single-cast cellular or wireless approach.  In fact, this will even allow the update of software, maps and other resources during a disaster.

We have even demonstrated it to deliver an SMS message between South Africa and Australia, using nothing but compatible phones to carry the message more than 10,000km:

This feature has profound utility in allowing the exchange of messages, files, and all manner of data in what are otherwise very difficult settings.

It also provides the capabilities required to enable disadvantaged communities, perhaps in remote locations, war zones or informal settlements, to create their own infrastructure, carrier and cost-free SMS networks using compatible handsets, so that they can enjoy the benefits of digital communications that many of us take for granted.

Early Prototype of the Serval Mesh File Distribution System, the Rhizome Retriever

Romain one of our team has been working hard to get the Rhizome Retriever together as part of our work in supporting citizen journalism in a community in Nigeria, that I have blogged about previously.

They are already using our software in that community to make free mesh telephone calls, but from the outset the plan has been to enable them to be citizen journalists, and to share news and information in their community.

To enable this, we are making our Rhizome Retriever (Serval RR), which basically lets you pick files on your phone, and put them up on the mesh, from where they will be automatically distributed to other phones on the mesh.

Mass file distribution on a mesh is usually fraught with difficulties, not the least of which is that the available bandwidth on a mesh halves (or worse) for each extra hop that you try to traverse.

So you can often get decent bandwidth to nearby nodes, but poor or intermittent connection to more distant nodes.

Also, the more people trying to transfer things many hops across the network reduces the available bandwidth for everyone.

So we decided to make the Serval RR only ever send data one hop to the nearest neighbours.  They can then in turn send data to their neighbours later on at their convenience.

As a result, Serval RR can already distribute even relatively large files, certainly into the several mega-byte range, without great difficulty, and without making the network unusable for everyone else.

Here is a quick demo of the initial prototype of the Serval RR software in action:

The importance of communications during emergencies

Early 2011 saw the worst floods in Queensland, Australia in 40 years.

Not surprisingly, this placed significant stresses on response efforts, and for a variety of reasons, the Queensland Government has issued an interim report on the event and what responses should be made.

You can read the interim report here.

I have been reading through this from a telecommunications perspective, and found the following items:


2.24  Seqwater should give consideration to posting information about current and future releases on its website during flood events as one method of ensuring accurate and timely information is available to the public. 


This may seem like a small matter, but by making the information available somewhere where someone in the community could access it, and possibly disseminate it further, perhaps by word of mouth, or perhaps by feeding it into a crowd-source incident reporting system such as Ushahidi or the Serval Rhizome/Mapping combination, where it could be made available to others who need it.  Indeed, this process could be automated, providing a very valuable community service.  However, if the information is not shared in the first instance, then such broad and means of distribution will be troublesome to implement, and potentially disadvantage many.

In short, putting information out where the public can get to it, and make further use of it supports resilience.



5.21 The Queensland Fire and Rescue Service should ensure that rescue technicians on deployment are provided with individual radios, rather than sharing a communications pack


Presumably the sharing of communications packs is related to their cost and bulk.
Using off-the-shelf meshing mobile phones would allow all rescue technicians to have a personal means of communications that makes use of the shared communications pack, relaying traffic back through that resource.



5.29 The Queensland Fire and Rescue Service should consider isolating repeaters during a large scale emergency response. If this solution is found to be feasible, it should be implemented as protocol as soon as possible. If it is not, the Queensland Fire and Rescue Service should explore other solutions to the issue of the fire communications network being overloaded and firefighters resorting to localised networks during large scale emergency response situation.


This seems to be responding to the issue of excessive traffic being relayed across the region, congesting the system and preventing it being of effective use.  The Serval Mesh system has the potential to localise message delivery to the local teams that need it (whether or not they are locally based), and still retaining the ability to broadcast messages over the whole region when suitably addressed.

This is not a particular mode we had considered greatly in the past, so this is a helpful thing for us to discover.


7.2 Lockyer Valley Regional Council should investigate the feasibility of installing alarm-activating gauges in the creeks at Spring Bluff, Murphys Creek and other communities where communication systems are poor and there is a risk of rapid and unexpected water rise.


This is interesting for us to read, as we are already contemplating creating a very similar system for use in the Mekong River Basin on conjunction with a Lao doctoral student here in the department.  The characteristics of the system are having a local mesh broadcast an alarm to all mesh nodes when one or more mesh-equipped sensors indicates a high water level.

It is possible that those sensors could be low-cost mobile telephones connected to a device such as the IOIO, creating a very simple and low-cost solution, provided the device can be powered, perhaps using a solar panel and modest storage battery, such as an old car battery no longer able to supply the peak load required to start a car, but more than sufficient for the couple of watts required to run a phone and sensor.

"SMS alerts are also not a reliable method of providing flood warnings in parts of Queensland which experience problems with telephone coverage. That difficulty is compounded during a flood, when telephone reception can be affected by flood related power outages and congested telecommunications networks."


This is precisely the kind of short coming with cellular networks that Serval has sought to find and create solutions for, that complement the existing infrastructure.  In particular, the ability of the Serval Rhizome mesh file/message distribution system to work asynchronously, and automatically share information carried in phones as they more from region to region has particular value in these sorts of situations.

Also, the ability place local calls on the mesh, and where possible, setup connections from the mesh to the outside world offers a significant capability that is otherwise a considerable liability in these situations.

The ability for Serval technology to allow the rapid setup of a local mobile telephone network, and then connect it to the global telecommunications network using the nearest functional mobile phone tower was demonstrated in Brisbane in late January 2011, just a couple of weeks after the flooding had subsided.

We did this by placing a phone running the Serval software at a high vantage point where it could communicate with the nearest functional mobile phone tower (we used a helium balloon, but a roof top, or even a long fishing pole gaffer taped to a car would suffice).  This then allowed the phones on the ground that were also running our software to relay calls out to the world.  Here is the video we took of us doing exactly this, and watching people use it:

Kicking The Infrastructure Habit

Last weekend I delivered the inaugural Jim Bettison Memorial Oration at the biannual Adelaide Festival of Ideas. This was a great honour, and my presentation was well received by the audience, as was evidenced by the poignancy of their questions.

Here is the abstract of my oration:

Modern communications systems use extensive and expensive infrastructure to deliver services we could only dream of a few decades ago. This works for those who enjoy peace and sufficient wealth, but fails to reach the last billion people in poorer countries, as well as those in remote, emergency or disaster situations. Now modern mobile phones have the potential to communicate directly, to form networks without reliance on any infrastructure. The Serval Project based at Flinders University is turning this dream into a reality. It is working to make communications available to everyone, anywhere, any time especially to those who need it most.

You can listen to the oration by downloading the MP3 from the Radio Adelaide website.

You can also listen to an ABC Bush Telegraph interview about the oration that I recorded a few days prior to the oration.

Australian Humanitarian Engineering Summit

Last week I attended the Humanitarian Engineering Summit in Brisbane, Australia.

You can read about it and watch a TV news report here at the Engineers Australia web site.

This was an interesting event. First, the attendees were an almost even spread across all age ranges, perhaps with a bias to the younger end.  All of these people were exploring what it means to be a humanitarian engineer, and what they and the engineering profession as a whole can do to address many of the challenges in the world.

It was extremely encouraging to see the passion and dedication of many of the younger delegates -- including many current Engineering students -- because one day soon they will be the generation of engineers ultimately defining by example what it means to be an engineer.

Perhaps one of the greatest themes of the day was that in trying to help communities in need, it is not sufficient or indeed appropriate to simply turn up with a "first world solution" set it going, and then leave.  The almost inevitable result is that the intervention fails, essentially because of lack of ownership and appropriateness -- both of which stem from the fundamental need for better consultation and inclusion of the community the intervention is serving.  I think that they are spot on.

For Serval, this means that we need to continue to engage with the potential target audiences of our technology, which we are already committed to doing.  Otherwise, we stand the risk of becoming irrelevant and useless for the very people we want to help, in which case we may as well pack up and go back to our old jobs.